Card link not underlined on hover

Created by: andrewpucci

As you can see on the sample card in the docs, hovering over an anchor with class card-link is not underlined.

In https://github.com/twbs/bootstrap/pull/30389, the default text-decoration for links is now to be underlined both on hover and not. For consistency's sake, it makes sense to me that card links should work the same way.

It seems to me that perhaps this class was missed in that PR.

Tested on macOS 11.4 and Firefox 89.0.2, but this should be independent of OS or browser.